CN104871361A - Mask-less fabrication of vertical thin film batteries - Google Patents

Abstract

A method of manufacturing a thin film battery, the method may comprise the steps of: depositing a first stack of cover layers on a substrate, the first stack comprising a cathode current collector, a cathode, an electrolyte, an anode, and an anode current collector; laser die patterning Thinning the first stack to form one or more second stacks, each second stack forming the core of an individual thin film battery; blanket depositing an encapsulation layer over the one or more second stacks; laser patterning the encapsulation layer , to open the contact area for the anode current collector on each of the one or more second stacks; blanket deposit a metal liner layer over the encapsulation layer and the contact area; and laser pattern the metal liner layer to electrically isolate An anode current collector for each of the one or more thin film cells. For non-conductive substrates, open the cathode contact area through the substrate.

Description

Maskless fabrication of vertical thin-film cells

Cross References to Related Applications

This application claims the benefit of US Provisional Application No. 61/739,635, filed December 19, 2012.

technical field

Embodiments of the invention generally relate to a maskless fabrication process for thin film batteries.

Background technique

Thin-film batteries (TFBs) are expected to dominate the micro-energy application space. TFBs are known to present several advantages over conventional battery technologies such as superior form factor, cycle life, power capacity and safety. Figure 1 shows a cross-sectional view of a typical thin film battery (TFB), and Figure 2 shows a flow chart for fabricating a TFB and a corresponding plan view of a patterned TFB layer. Figure 1 shows a typical horizontal TFB device structure 100 with an anode current collector 103 and a cathode current collector 102 formed on a substrate 101, followed by a cathode 104, an electrolyte 105 and an anode 106, however the device can have the cathode , electrolyte and anode are fabricated in reverse order. Furthermore, the cathode current collector (CCC) and the anode current collector (ACC) can be deposited separately. For example, CCC can be deposited before the cathode, and ACC can be deposited after the electrolyte. The device may be covered by an encapsulation layer 107 to protect environmentally sensitive layers from oxidizing agents. See, eg, N.J. Dudney, Materials Science and Engineering B 116, (2005) 245-249. Note that these component layers of the TFB device shown in Figure 1 are not drawn to scale.

However, challenges remain to be overcome to allow cost-effective high volume manufacturing (HVM) of TFBs. Crucially, the current state-of-the-art TFB device patterning technique (ie, shadow masking) used during physical vapor deposition (PVD) of these device layers requires an alternative technique. There are significant complexities and costs associated with the use of light-shielding masking processes in HVM: (1) significant capital investment is required in the equipment used to manage, precisely align and clean these masks, especially for large area substrates; (2) little utilization of substrate area due to the necessity to accommodate deposition below the shadow mask edge and limited alignment accuracy; and (3) constraints on the PVD process to avoid alignment problems induced by thermal expansion , that is, low power and low temperature.

In the HVM process, the utilization of light-shielding masks (prevalent in traditional and current state-of-the-art TFB fabrication techniques) will result in higher complexity and higher cost in fabrication. Complexity and cost arise from the need to manufacture highly accurate masks and (automatic) management systems for mask alignment and regeneration. Cost and complexity can be extrapolated from the well-known photolithography processes used in the silicon-based integrated circuit industry. Furthermore, the costs arise from the need to maintain these masks and the throughput limitations caused by the added alignment steps. Adaptation becomes more difficult and expensive when scaling up to larger area substrates for fabrication for improved throughput and economies of scale (ie, HVM). Furthermore, the scale-up (to larger substrates) may itself be limited due to the limited availability and capabilities of light-shielding masks.

Another effect of using a blackout mask is the reduced utilization of a given substrate area, resulting in non-optimal cell density (battery charge, battery energy, and battery power). This is because shadow masks do not fully restrict the deposition of sputtered species beneath these masks, leading to some minimum non-overlapping requirements between successive layers in order to maintain electrical isolation between critical layers. In addition, there are inherent alignment limitations from inaccuracies in mask fabrication and alignment accuracy of alignment tools. This alignment inaccuracy is further exacerbated by the thermal expansion mismatch between the substrate and the mask, as well as different thermal conditions during deposition. The consequence of this minimum non-overlapping requirement is a loss of cathode area, resulting in a total loss of capacity, energy and power content of the TFB (all other things being equal).

A further impact of the shadow mask is limited process throughput, since additional thermally induced alignment problems must be avoided, i.e., thermal expansion of the mask causing warping of the mask, and movement of the mask edges away from these masks relative to The alignment position of the substrate. Consequently, PVD yields are lower than desired because the deposition tools are operated at low deposition rates to avoid heating the masks beyond process tolerances.

Furthermore, processes using physical (blackout) masks often suffer from particle contamination which ultimately impacts yield.

Therefore, there remains a need for concepts and methods to significantly reduce the cost of HVM for TFBs by enabling TFB process technology to be simplified and more compatible with HVM.

Contents of the invention

This paper describes a novel vertical thin-film battery in which the anode and cathode are electrically connected outward from the top membrane side and the bottom substrate, respectively. This vertical TFB structure not only increases substrate utilization and yield, but also simplifies the TFB fabrication process. Note that the term cathode in this text is used to describe an electrode where a reduction reaction occurs at the same time as an oxidation reaction at the anode, that is, one electrode will function as both cathode and anode, although not simultaneously, depending on the electrochemical reaction taking place direction. For example, in one orientation, the _LiCoO2 layer is the cathode, and in the other orientation, the _LiCoO2 layer is the anode.

The present invention utilizes vertical TFB structures, blanket deposition of TFB layers, and ex situ laser patterning of blanket layers to improve yield, throughput, patterning accuracy, and increase die density. The novel vertical TFB structure can not only increase substrate utilization and yield, but also simplify the TFB manufacturing process. The blanket layer deposition removes the need for a shadow mask, which not only removes the high cost of fabricating and cleaning the masks, especially for large area substrates, but also removes any constraints on the PVD process, which are defined by Potential thermal expansion-induced alignment issues and interactions between additional magnets and the RF PVD process arise. The concept of continuous blanket deposition of all active layers on a single substrate without breaking vacuum (except for the need for cathodic annealing after deposition) significantly increases film deposition throughput and reduces laser ablation. ) steps and challenges. Because the adverse reactions generated by contact with surrounding oxidants during exposure are minimized, these adverse reactions are that hygroscopic LiPON can absorb H ₂ O in the environment/with H ₂ O in the environment (the H ₂ O in the environment is likely to be in the Reaction with Li during the subsequent Li deposition step creates an unwanted interfacial layer and an additional source of cell impedance, so reducing environmental exposure can also improve device performance. Vertical TFB structures, blanket deposition, and ex-situ laser patterned TFBs improve pattern accuracy, yield, and substrate/material usage, and have great potential to reduce the manufacturing cost of TFBs far below current costs.

According to some embodiments of the present invention, a method of manufacturing a thin film battery may include the steps of depositing a first stack of capping layers on a conductive substrate, the first stack including a cathode current collector layer, a cathode layer (annealing the layer), electrolyte layer, anode layer, and anode current collector layer; laser die patterning the first stack to form one or more second stacks (each second stack forming the core of an independent TFB); Depositing an encapsulation layer over one or more second stacks; laser patterning the encapsulation layer to open contact areas for the ACC on each of the one or more individual stacks; repeatable depending on appropriate requirements for permeation barrier performing repeated blanket deposition of an encapsulation layer and subsequent patterning of the ACCs; blanket deposition of a metal padlayer over the contact areas of the encapsulation layer and the ACCs; and laser patterning of the metal padlayer to Electrically isolating the ACC of each of the one or more TFBs, this step may be achieved by laser dicing to obtain individual TFBs.

According to other embodiments of the present invention, a method of manufacturing a thin film battery may include the steps of: depositing a first stack of cover layers on a non-conductive substrate, said first stack including a die patterned auxiliary layer (optional), Cathode current collector layer, cathode layer (anneal the layer as needed), electrolyte layer, anode layer and anode current collector layer; laser die patterning the first stack to form one or more second stacks (each second stack to form the core of an independent TFB); blanket depositing an encapsulation layer on top of the one or more second stacks; laser patterning the encapsulation layer for ACC on each of the one or more second stacks opening the anode contact area; blanket depositing a metal liner layer over the encapsulation layer and the anode contact area of the ACC; laser patterning the metal liner layer to electrically isolate the ACC of each of the one or more TFBs; and piercing The cathode contact area on the cathode current collector of each of the one or more thin film batteries is opened through the substrate.

Furthermore, the present invention describes means for carrying out the methods described above.

According to other embodiments of the invention, a thin film battery may comprise: a stack of layers on the top surface of a non-conductive substrate, the stack comprising a cathode current collector layer, a cathode layer, an electrolyte layer, an anode layer and an anode current collector layer; an encapsulation layer completely covering the stack of layers except for at least one opening to said anode current collector layer (for electrical contact with said anode layer); and a metal backing layer in contact with the anode current collector layer at at least one opening in the encapsulation layer; wherein the substrate has an opening leading to the cathode current collector for contact with the cathode layer electrical contact.

Description of drawings

These and other aspects and features of the present invention will become apparent to those of ordinary skill in the art upon reading the following description of specific embodiments of the invention in conjunction with the accompanying drawings, in which:

Figure 1 is a cross-sectional view of a thin film battery (TFB);

Fig. 2 is the flowchart of making TFB, and the corresponding plan view of patterned TFB layer;

3A-3F are cross-sectional views of sequential steps in a first process flow for fabricating a vertical TFB with a conductive substrate according to some embodiments of the present invention;

4A-4G are cross-sectional views of sequential steps in a second process flow for fabricating a vertical TFB with a non-conductive substrate according to some embodiments of the present invention;

5A-5C are cross-sectional and plan views of sequential steps in a third process flow for fabricating a vertical TFB with a non-conductive substrate, according to some embodiments of the present invention;

Figures 6A and 6B are surface profiler traces across the edge of a vertical TFB that was scanned from the backside (substrate side) and front side of the substrate by a 532 nm nanosecond laser, respectively, according to some embodiments of the present invention. Side (film side) patterning;

Figure 7 is a schematic diagram of a laser patterning tool according to some embodiments of the present invention;

8 is a schematic diagram of a thin film deposition cluster tool for fabricating vertical TFBs according to some embodiments of the present invention;

9 is a representative diagram of a thin film deposition system with multiple in-line tools for fabricating vertical TFBs according to some embodiments of the present invention; and

10 is a representative diagram of a tandem deposition tool used to fabricate vertical TFBs according to some embodiments of the present invention.

Detailed ways

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings, provided as illustrative examples of the invention so that those skilled in the art can practice the invention. The drawings provided herein are merely representative views of devices and device process flows and are not drawn to scale. Notably, the following figures and examples are not meant to limit the scope of the invention to a single embodiment, and other embodiments are possible through the interchange of some or all of the described or illustrated elements. Furthermore, when some elements of the present invention can be partially or completely implemented using known components, only those parts of these known components necessary for understanding the present invention will be described, and descriptions of other parts of these known components will be omitted. The detailed description is so as not to obscure the invention. In this specification, an embodiment showing a single component should not be considered limiting; rather, the invention is intended to cover other embodiments comprising a plurality of the same component, and vice versa, unless expressly stated otherwise herein. . Furthermore, applicants do not intend for any term in the specification or claims to be ascribed an uncommon or special meaning unless expressly stated otherwise. Additionally, the present invention encompasses present and future known equivalents to known components referred to herein by way of illustration.

In conventional TFB fabrication, all layers are patterned using an in-situ shadow mask, through backside magnets, Tape or by using some fixtures to hold the stack together to fix the in-situ shadow mask to the device substrate. Furthermore, the anode and cathode current collectors of conventional TFBs (such as the TFB of FIG. 1 ) are usually connected outwards on the same side of the device. According to an embodiment of the present invention, a vertical TFB cell structure is proposed herein, the anode and cathode of which are electrically connected outwards from the top membrane side and the bottom substrate, respectively. Compared with conventional TFB configurations, this vertical TFB configuration greatly increases substrate utilization and yield. In the present invention, instead of in situ patterned deposition, blanket deposition without using any shadow mask is proposed for all layers in TFB fabrication, including bonding pads and protective coatings. This flow can also be incorporated into processes for bonding, encapsulation and/or protective coating. Patterning of the cover layer can be performed by a laser ablation process.

All active layers of the vertical TFB (cathode current collector, cathode, electrolyte, anode and anode current collector) can be deposited continuously overlay, possibly without breaking vacuum. This significantly increases film deposition throughput.

The entire TFB process requires only three laser steps: the first laser step is to isolate/define the TFB die, which can be performed from the backside using low laser fluence; the second laser step is to ablate the encapsulation layer/Li protective layer to open the Areas for depositing bonding pads on the ACC; the final laser step is to ablate the photoresist and/or substrate from the backside.

According to some embodiments of the present invention, a method of manufacturing a thin film battery may include the steps of depositing a first stack of capping layers on a conductive substrate, the first stack including a cathode current collector layer, a cathode layer (annealing the layer), electrolyte layer, anode layer, and anode current collector layer; laser die patterning the first stack to form one or more second stacks (each second stack forming the core of an independent TFB); Depositing an encapsulation layer over one or more second stacks; laser patterning the encapsulation layer to open contact areas for the ACC on each of the one or more individual stacks; repeatable depending on appropriate requirements for permeation barrier Performing repeated blanket deposition of an encapsulation layer and subsequent ACC patterning; blanket deposition of a metal liner layer over the contact areas of the encapsulation layer and the ACCs; and laser patterning of the metal liner layer to electrically isolate one or ACC for each of more TFBs, this step can be achieved by laser cutting to obtain individual TFBs.

In more detail, as shown in the examples of FIGS. 3A-3F , the process begins by providing a conductive substrate 301 , such as a stainless steel substrate. In FIG. 3A , blanket deposition of the following layers on the substrate is shown: CCC 302 , cathode 303 , electrolyte 304 , anode 305 and ACC 306 . Examples of materials for each of these layers are: CCC is Pt plus an adhesion layer such as Ti or Ti/Au; the cathode is LiCoO ₂ ; the electrolyte is LiPON; the anode is Li or Si; It is Ti/Au or Cu. After depositing the cathode layer, the cathode can be annealed, for example at 600° C. or above for two hours or more, in order to create a crystalline structure. Non-Li anode cells can be dry lithiated during these steps if desired. (For example, take the vanadium oxide cathode layer. If the counter electrode or anode is not Li, then a charge carrier will need to be added to the "system". This can be done using the so-called dry lithiation process The process includes: depositing a cathode layer, and if necessary annealing the cathode layer; and depositing Li over the cathode. If a shadow mask process is used for the cathode, then the same shadow mask can be used. The deposited lithium "reacts/intercalates" with the cathodic layer, forming a lithiated cathodic layer. The same procedure can be followed for the anode side if it is another intercalation compound or composite/reactive base material such as Sn and Si. General procedure.) In Figure 3B, laser die patterning can be used to form one or more individual devices (the figure shows only one device, however, multiple devices can be formed on a single substrate); Oxidation can be achieved by front-side or back-side laser radiation. In FIG. 3C , an encapsulation layer 307 is deposited overlay; the encapsulation layer can be deposited by, for example, dielectric deposition or polymer deposition or a combination of both. In Figure 3D, front side laser patterning can be used to remove the encapsulation layer to open the contact area of the ACC. The steps of Figure 3C and Figure 3D can be repeated to meet the requirements of the permeation barrier. In FIG. 3E, a contact liner layer 308, which may be a metal such as Al or Cu, is deposited overlying for eventual connection to external circuitry. In Figure 3F, the pads are laser ablated from the dicing alley; however, the encapsulation layer can be left on the substrate for better electrical isolation. Laser cutting can then be used to obtain individual devices. In addition, more protective layers (organic, dielectric or metallic) can be deposited and patterned if desired.

According to other embodiments of the present invention, a method of manufacturing a thin film battery may include the steps of: depositing a first stack of cover layers on a non-conductive substrate, said first stack including a die patterned auxiliary layer (optional), Cathode current collector layer, cathode layer (anneal the layer as needed), electrolyte layer, anode layer and anode current collector layer; laser die patterning the first stack to form one or more second stacks (each second stack to form the core of an independent TFB); blanket depositing an encapsulation layer on top of the one or more second stacks; laser patterning the encapsulation layer for ACC on each of the one or more second stacks opening the anode contact area; blanket depositing a metal liner layer over the encapsulation layer and the anode contact area of the ACC; laser patterning the metal liner layer to electrically isolate the ACC of each of the one or more TFBs; and piercing The cathode contact area on the cathode current collector of each of the one or more thin film batteries is opened through the substrate.

In more detail, as shown in the example of FIGS. 4A-4G , the process starts by providing a non-conductive substrate 401 such as Si ₃ N ₄ /silicon, mica or glass. (Note that if a Si substrate is used, to make the substrate "non-conductive", a dielectric can be deposited on the surface prior to depositing the stack, and after the step shown in Figure 4G, a further laser ablation step will be required to open the bottom contact). In FIG. 4A , blanket deposition of the following layers on the substrate is shown: die patterned assist layer 402 , CCC 403 , cathode 404 , electrolyte 405 , anode 406 and ACC 407 . Examples of materials for each of these layers are: a die-patterned assist layer is an amorphous silicon (a-Si) layer or a microcrystalline silicon (μc-Si) layer; CCC is Pt plus an adhesion layer such as Ti ) or Ti/Au; the cathode is LiCoO ₂ ; the electrolyte is LiPON; the anode is Li or Si; and the ACC is Ti/Au or Cu. After depositing the cathode layer, the cathode can be annealed. Non-Li anode cells can be dry lithiated during these steps if desired. In Figure 4B, laser die patterning can be used to form one or more individual devices (only one device is shown in this figure, however, multiple devices can be formed on a single substrate); Side or back side laser radiation is achieved. In FIG. 4C , an encapsulation layer 408 is deposited overlay; the encapsulation layer can be deposited by overlay dielectric or polymer or a combination of both, such as SiN/polymer/SiN/polymer. In Figure 4D, the encapsulation layer is removed using frontside laser patterning to open the contact area of the ACC; in addition, frontside or backside laser irradiation can be used to remove thin strips of the encapsulation layer adjacent to the edges of the stack (strip) (these strips are approximately the thickness of the encapsulation layer from the edge of the stack), while the remainder of the encapsulation layer is left in the dicing lane to facilitate the dicing process. The thin strips may have a width in the range of 10 microns to 1000 microns, in embodiments 10 microns to 500 microns, in other embodiments 30 microns to 200 microns. (Note that the remaining encapsulation layer on the dicing tracks reduces defects caused by dicing the substrate material and can also be used as an alignment guideline.) The purpose of removing the encapsulation layer adjacent to the edge of the stack is for subsequent pads Metal 409 deposition will act as an additional permeation barrier. In FIG. 4E , a contact liner layer 409 is deposited overlay, which may be a metal such as Al or Cu. (When to avoid alloying with Li, such as when a Li anode is used, the contact liner layer 409 may be Cu.) In FIG. 4F, the liner layer and encapsulation layer are laser ablated from the dicing lanes. To accomplish this, two different process flows are provided as examples, the first being a laser-based process and the second being an etch-based process.

In the first process flow, as shown in Figure 4G, the substrate is laser ablated to expose the CCC, allowing backside contacts to be made through the substrate. Typically, ultrafast lasers are used to etch through the substrate without damaging the CCCs. In addition, when the laser removal process is close to CCC, the ultrafast laser fluence can be controlled to less than The rate per pulse removes layers and thus minimizes removal of CCC material. The backside contact may be formed by another vacuum deposition, or may be formed by applying a conductive slurry or paste. Contacts to external circuitry can be made using bonding techniques or soldering. Cutting is usually made after backside contact is established. In addition, more protective layers (organic, dielectric or metallic) can be deposited and patterned if desired.

As shown in FIG. 5A, in a second process flow, starting with the structure in FIG. 4F, the device is inverted and photoresist 410 is spin-coated on the backside of the substrate. In Figure 5B, the photoresist (or some etch resistant polymer) 410 is laser ablated to expose the substrate where vias to the CCC will be formed. More protective layers (dielectric, organic or metallic) can be deposited and patterned at this point in the process if desired. In Figure 5C, the substrate is etched to form vias to the CCC. Conventional dry etch and wet etch processes can be used to etch through the substrate and expose the CCC. Examples of etches expected to be effective for glass substrates include: (1) buffered hydrofluoric acid solution, this etch is standard for _SiO2 and consists of 6 volumes of _ammonium fluoride (NH4F, 40% solution) and 1 volume HF composition; (2) so-called P-type etching, that is, 60 volumes of H ₂ O + 3 volumes of HF + 2 volumes of HNO ₃ ); and TMAH (tetramethylammonium hydroxide), TMAH can provide some metal very good etch selectivity. An example of an etch expected to be effective for silicon substrates is Potassium Hydroxide (KOH), although crystallographic etch should be considered to be preferable; also some photoresist materials will not hold up in KOH, so appropriate resistivity is required. etched polymer. Note that although removal of the polymer layer may improve volumetric energy density, it is not necessary to remove the polymer layer and can function as a protective coating.

To further discuss the above-mentioned die-patterned auxiliary layer, a more detailed description is provided below. When the die patterning starts from the substrate side through which the laser beam passes before reaching the deposited layer, the die patterns the auxiliary layer (e.g., an amorphous silicon (a-Si) layer or a microcrystalline silicon (μc-Si) layer) can be used to achieve die patterning/ablation of the entire stack indirectly by using the vapor pressure of the auxiliary layer without individually melting/evaporating the other stack layers, which greatly reduces the laser energy required to remove material , and improve the quality of die patterning.

Laser processing and ablation patterning can be designed to form TFBs with the same device structure as those fabricated using masks, but more precise edge placement can provide higher device density and other design improvements. Some embodiments of the process of the present invention are expected to have higher yields and device densities for TFBs compared to current shadow mask fabrication processes, since use of a shadow mask in the TFB fabrication process is likely to be a yield-reducing defect source, and removing the shadow mask removes these defects. It is also expected that some embodiments of the process of the present invention will provide better patterning accuracy than the shadow mask process, which will allow for higher TFB device densities on the substrate. In addition, some embodiments of the present invention are expected to relax the PVD process constraints (limited by lower power and temperature in the shadow mask deposition process) caused by alignment problems induced by potential thermal expansion of the shadow mask, And increase the deposition rate of the TFB layer.

Additionally, removing the shadow mask from the TFB fabrication process reduces the cost of the new fabrication process by: eliminating mask aligners, mask management systems, and mask cleaning; reducing COC (cost of consumables); and allowing the use of Industry-proven process for the silicon integrated circuit and display industry. Cap layer deposition and ex-situ laser patterning of TFBs can improve pattern accuracy, yield, and substrate/material usage to substantially drive down TFB manufacturing costs.

Conventional laser scribing or laser projection techniques can be used for the selective laser patterning process of the present invention. The number of lasers can be: one, e.g., a UV/VIS laser with picosecond or femtosecond pulse width (selectivity controlled by laser fluence/dose); two, e.g., a combination of UV/VIS and IR lasers (selectively controlled by Laser wavelength/flux/dose control selectivity); or multiple (selectivity controlled by laser wavelength/flux/dose). The scanning method of the laser scribing system can be galvanometer stage movement, beam movement, or both. The laser spot size of the laser scribing system can be adjusted from 30 microns (mainly for die patterning) to 1 cm (diameter, diagonal or other feature length). The laser area at the substrate for the laser projection system can be 1 mm ² or more, where the energy distribution within the beam ideally has a top hat profile. Additionally, other laser types and configurations may be used.

Note that it may be desirable to use these metal current collectors on both the cathode and anode sides as a protective barrier for shuttling lithium ions. In addition, it may be desirable to use the anode current collector as a barrier to oxidizing agents ( _H2O , _O2 , _N2 , etc.) from the environment. Therefore, the selected material or materials should have minimal reactivity or miscibility when in contact with Li in "two directions", i.e., Li moves into the metal current collector to form a solid solution. , and vice versa. In addition, the materials selected for metal current collectors should have low reactivity and diffusivity for those oxidizing agents. Based on published binary phase diagrams, some potential candidate elements for the first requirement are Ag, Al, Au, Ca, Cu, Co, Sn, Pd, Zn and Pt. For some materials, it may be necessary to manage the thermal budget to ensure no reaction/diffusion between metal layers. If a single metal element cannot meet these two requirements, alloys can be considered. Furthermore, if a single layer cannot satisfy both requirements, a double layer (multilayer) can be used. In addition, an additional adhesion layer may be used in combination with one of the refractory and non-oxidizing layers described above, for example, a Ti adhesion layer in combination with Au or Pt. The current collector can be deposited by (pulsed) direct current sputtering of a metal target to form a layer (for example, a metal such as Cu, Ag, Pd, Pt and Au, a metal alloy, a metalloid or carbon black). The stack of layers forming the current collector (including adhesion layers, etc.) can typically have a thickness of up to 500 nm. Furthermore, there are other options for forming a protective barrier against the reciprocating lithium ions, such as dielectric layers and the like.

Radio frequency sputtering has been the traditional method of depositing cathode layers (eg LiCoO2) and electrolyte layers (eg _Li3PO4 in _{N2 )} , where both layers are insulators ₍ especially the electrolyte). However, pulsed DC and pure DC methods are also used for _LiCoO2 deposition. Additionally, other deposition techniques may be used, including applying a substrate bias. Additionally, multiple frequency radio frequency sputtering techniques can be used, for example, as described in U.S. Patent Application Publication No. 2013/0248352, "Multiple Frequency Sputtering for Enhancement in Deposition Rate and Growth Kinetics of Dielectric Materials," published September 26, 2013 technology. The Li layer 305/406 can be formed using evaporation or sputtering processes. The Li layer may be a Li alloy, for example, where Li is alloyed with a metal such as tin or a semiconductor such as silicon. The thickness of the Li layer can be about 3 μm (suitable for cathode and capacitive balancing, and as a reservoir for degradation by oxidant permeation over the expected lifetime of the device), and the thickness of the encapsulation layer 307/408 can be 3 μm or thicker. The encapsulation layer can be multiple layers of parylene/polymer and metal and/or dielectric. Note that the part must be maintained in an inert environment, such as argon or (very) dry air, between the formation of the Li layer 305 and the encapsulation layer 307; environmental requirements. ACC 306/407 can be used to protect the Li layer to allow laser ablation outside vacuum and to relax the requirement for an inert environment. However, it may be best to still maintain this environment to minimize oxidant penetration.

As noted above, FIGS. 6A and 6B illustrate the surface profiler trace across the edge of the laser patterned stack after die patterning. In Figure 6A, laser patterning starts from the backside (through the substrate), and in Figure 6B, laser patterning starts from the front (film) side. The film stack in this particular example was Ti/Au/LiCoO2 _on a glass substrate, and all capping stack layers were deposited by DC pulsed magnetron. The laser used for ablation was a nanosecond laser at 532 nm with a spot size of approximately 40 microns. From Figure 6A it is clear that there are few spikes in the ablated area. This is in contrast to patterning the same stack from the film side using a nanosecond laser at 532nm or 1064nm, which results in leaving an unacceptable amount of debris in the ablated area in the form of "spikes" of material (as shown in Figure 6B). If die-patterned from the substrate side, there are few "spikes" in the ablated area, whereas if die-patterned from the device side, there are many large "spikes" in the ablated area. Laser patterning from the substrate side is an explosive process before the "upper" layer is melted, whereas patterning from the film side requires ablation of the entire film stack. Laser patterning from the substrate side requires much less laser fluence than from the film side, especially for multiple thick film stacks. Furthermore, laser patterning from the film side must first melt and then vaporize all of the film stack, and the melt discharge forms a "spike" that remains in the ablated area.

Furthermore, for substrate-side laser ablation using a 532nm nanosecond laser with a PRF (Pulse Repetition Frequency) of 30kHz, a wide process window was observed in experiments with laser current variations from 24A to 30A and scan speeds from 400mm Variations from /s to 1000mm/s showed excellent edge definition without significant residue in the removed area.

FIG. 7 is a schematic diagram of a laser patterning tool 700 according to an embodiment of the invention. Tool 700 includes a laser 701 for patterning a device 703 on a substrate 704 . Also shown is laser 702 patterning through substrate 704, although laser 701 could be used to pattern through substrate 704 if the substrate is flipped over. A substrate holder/platform 705 is provided for holding and/or moving a substrate 704 . Platform 705 may have holes to accommodate laser light patterned through the substrate. The tool 700 can be configured to hold the substrate during laser ablation, or to move the substrate, and the lasers 701/702 can also be fixed or movable; in some embodiments, both the substrate and the laser are movable, And in this case the movement is coordinated by the control system. FIG. 7 shows a stand-alone version of tool 700, including SMF 760 with glove box 780 and antechamber 770. The embodiment shown in Figure 7 is an example of a tool according to the invention, many other arrangements of the tool are conceivable, eg a glove box may not be necessary in the absence of lithium TFB. Additionally, tool 700 may be located in a chamber with a suitable environment, such as a dry chamber used in lithium foil fabrication.

Figure 8 is a schematic diagram of a processing system 800 for fabricating TFB devices according to some embodiments of the invention. The processing system 800 includes a standard mechanical interface (SMIF) 810 to a cluster tool 820 equipped with a standard or reactive plasma cleaning (PC or PRC) chamber 830 and processing chamber that can be used in the process steps described above Compartments C1-C4 (841-844). A glove box 850 may also be attached to the cluster tool if desired. A glove box can store substrates in an inert environment (eg, under an inert gas such as He, Ne or Ar), which is useful after alkali metal/alkaline earth metal deposition. If desired, a front chamber 860 to the glove box can also be used, which is a gas exchange chamber (inert gas is exchanged for air and vice versa), which allows for Pass the substrates in and out of the glove box without any problems. (Note that the glove box can be replaced with a dry room environment with a sufficiently low dew point, such as that used by lithium foil manufacturers.) Chambers C1-C4 can be configured for process steps in the fabrication of thin-film battery devices, which can include The following steps: deposition of cathode layer (e.g., by RF sputtering LiCoO ₂ ); deposition of electrolyte layer (e.g., in N2 by RF sputtering of Li ₃ PO ₄ ); deposition of alkali or alkaline earth metals; and selective laser patterning overlay layer. Examples of suitable cluster tool platforms include AKT's display cluster tool, such as the 10th generation display cluster tool, or Applied Material's Endura ^™ and Centura ^™ for smaller substrates. Conventional furnace and radiant heating can suffice for annealing requirements, including microwave annealing as described in "Microwave Rapid Thermal Processing of Electrochemical Devices," US Patent Application Publication No. 2013/0266741, published October 10, 2013. It should be understood that while processing system 800 has been shown as a cluster arrangement, a linear system could also be used in which processing chambers are arranged in a row without transfer chambers so that substrates are continuously moved from one chamber to the next. a chamber.

Figure 9 shows a representative diagram of an inline manufacturing system 900 having multiple inline tools 910, 920, 930, 940, etc., according to some embodiments of the invention. The tandem tools may include tools for depositing and patterning all layers of the TFB device. Additionally, in-line tools may include preconditioning and postconditioning chambers. For example, the tool 910 may be a pump down chamber for establishing a vacuum prior to moving the substrate through a vacuum airlock 915 into the deposition tool 920 . Some or all of the inline tools may be vacuum tools separated by vacuum airlock 915 . Note that the order of process tools and specific process tools in a process line will be determined by the specific TFB device fabrication method used, four specific examples of which are provided above. In addition, substrates can be moved through horizontally or vertically oriented in-line fabrication systems. Additionally, a selective laser patterned module can be configured to hold the substrate, or move the substrate, during laser ablation.

To illustrate the movement of substrates through an inline manufacturing system such as that shown in FIG. 9 , FIG. 10 shows a substrate carousel 1050 with only one inline tool 910 in place. Substrate holders 955 including substrates 1010 (the substrate holders are shown partially cut away so that the substrates can be seen) are mounted on a conveyor belt 950 or equivalent for moving the holders and substrates through the in-line tool 910, as As shown in the figure. Suitable in-line platforms for processing tool 910 may be Applied Materials' Aton ^™ and New Aristo ^™ .

An apparatus for forming a thin film battery according to an embodiment of the present invention may include a first system for blanket depositing a first stack on a substrate, the first stack including a cathode current collector layer, a cathode layer (anneal the layer as desired), an electrolyte layer, an anode layer, and an anode current collector layer; a second system for laser die patterning the first stack to form one or more first Two stacks, each second stack forming the core of an independent thin film battery; a third system, the third system is used to overlay deposit an encapsulation layer on top of one or more second stacks; a fourth system, the fourth system for laser patterning said encapsulation layer to open an anode contact area of an anode current collector on each of one or more second stacks; a fifth system for said encapsulation layer depositing a metal liner layer overlying and over the anode contact area; and a sixth system for laser patterning the metal liner layer to electrically isolate each of the one or more thin film cells Anode current collector. If desired, the seventh system can be used for cathodic annealing, or the in-situ annealing can be performed in the first system. In addition, when non-conductive substrates are used, it may be necessary to use other systems, such as laser ablation systems and/or etching systems, for opening through the substrate on the cathode current collector of each of the one or more thin film cells. the cathode contact area. These systems can be cluster tools, serial tools, stand-alone tools, or a combination of one or more of the aforementioned tools. Additionally, these systems may include tools that are common to one or more other systems, eg, one laser patterning tool may be used for more than one laser patterning step.

Although the invention has been described herein with reference to TFBs, the teachings and principles of the invention can also be applied to improved methods of fabricating other electrochemical devices, including electrochromic devices.

Although the present invention has been particularly described with reference to certain embodiments thereof, it will be apparent to those skilled in the art that changes in form and detail may be made and changes may be made without departing from the spirit and scope of the invention. Revise.

Claims (15)

1. manufacture a method for hull cell, said method comprising the steps of:

On electrically-conductive backing plate, first of sedimentary cover is stacking, and described first stackingly comprises cathode collector layer, cathode layer, dielectric substrate, anode layer and anode collector layer;

Described in laser punch die patterning, first is stacking, second stacking to form one or more, the core of each second stacking formation free standing film battery;

Described one or more second stacking on cover depositing encapsulation layer;

Encapsulated layer described in laser patterning, thinks that the described anode collector in one or more second stacking each described opens contact area;

Plated metal laying is covered on described encapsulated layer and described contact area; With

Metal liner layers described in laser patterning, with the described anode collector of each of one or more hull cell described in electric isolution.

2. the method for claim 1, further comprising the steps: after the step of encapsulated layer described in described laser patterning and before the step of the described metal liner layers of described covering deposition, cover deposition second encapsulated layer, and the second encapsulated layer described in laser patterning, to open described contact area.

3. the method for claim 1, the step of metal liner layers described in wherein said laser patterning is the described electrically-conductive backing plate that layer that laser cutting is included described metal liner layers covers, to be physically separated described independent TFB.

4. the method for claim 1, wherein said anode layer is lithium layer.

5. manufacture a method for hull cell, said method comprising the steps of:

On the top surface of non-conductive substrate, first of sedimentary cover is stacking, and described first stackingly comprises cathode collector layer, cathode layer, dielectric substrate, anode layer and anode collector layer;

Described in laser punch die patterning, first is stacking, second stacking to form one or more, the core of each second stacking formation free standing film battery;

Described one or more second stacking on cover depositing encapsulation layer;

Encapsulated layer described in laser patterning, thinks that the described anode collector in one or more second stacking each described opens positive contact region;

Plated metal laying is covered on described encapsulated layer and described positive contact region;

Metal liner layers described in laser patterning, with the described anode collector of each of one or more hull cell described in electric isolution; With

The cathode contact region on the described cathode collector of each of one or more hull cell described is opened through described substrate.

6. method as claimed in claim 5, wherein said first stackingly comprises punch die patterning auxiliary layer further, and described punch die patterning auxiliary layer is between described non-conductive substrate and described cathode collector layer.

7. method as claimed in claim 5, the wherein said step opening cathode contact region comprises: substrate described in laser ablation.

8. method as claimed in claim 5, described in wherein said laser patterning, the step of encapsulated layer comprises further: remove completely at described second stacking perimeter and be adjacent to the band of the described encapsulated layer at described second stacking edge, and described band is about the thickness of described encapsulated layer apart from described second stacking edge.

9. method as claimed in claim 5, the wherein said step opening cathode contact region comprises:

Resist is deposited on the basal surface of described substrate;

Remove the some parts of described resist, to expose some regions of the described basal surface of described substrate; With

Described substrate is etched through, to expose described cathode contact region at exposed region place.

10., for the manufacture of an equipment for hull cell, described equipment comprises:

The first system, described the first system is stacking for first of sedimentary cover on substrate, and described first stackingly comprises cathode collector layer, cathode layer, dielectric substrate, anode layer and anode collector layer;

Second system, described second system to be used for described in laser punch die patterning first stacking, second stacking to form one or more, the core of each second stacking formation free standing film battery;

3rd system, described 3rd system be used for described one or more second stacking on cover depositing encapsulation layer;

Quaternary system is united, and described Quaternary system system is used for encapsulated layer described in laser patterning, thinks that the described anode collector in one or more second stacking each described opens positive contact region;

5th system, described 5th system is used for covering plated metal laying on described encapsulated layer and described positive contact region; With

6th system, described 6th system is used for metal liner layers described in laser patterning, with the described anode collector of each of one or more hull cell described in electric isolution.

11. equipment as claimed in claim 10, wherein said second system is identical system with described Quaternary system system.

12. equipment as claimed in claim 10, wherein said substrate is non-conductive substrate, and described equipment comprises the 7th system further, described 7th system is used for through described substrate, opens the cathode contact region on the described cathode collector of each of one or more hull cell described.

13. equipment as claimed in claim 10, wherein said substrate is electrically-conductive backing plate.

14. 1 kinds of hull cells, described hull cell comprises:

Layer stacking, is describedly stackingly positioned on the top surface of non-conductive substrate, describedly stackingly comprises cathode collector layer, cathode layer, dielectric substrate, anode layer and anode collector layer;

Encapsulated layer, described encapsulated layer except leave towards described anode collector layer for at least one opening of described anode layer electrical contact except, cover the stacking of described layer completely; With

Metal liner layers, described metal liner layers at least one opening part described in described encapsulated layer contacts with described anode collector layer;

Wherein said substrate have towards described cathode collector for the opening with described cathode layer electrical contact.

15. hull cells as claimed in claim 14, wherein said metal liner layers covers described encapsulated layer completely.